Sealing means for cylinder papermaking machines



NOV. 3 1954 J. BAXTER, JR 2,695,550

SEALING MEANS FOR CYLINDER PAPERMAKING MACHINES Filed March 31, 1951 31 a 2 24 L H v as 16 3 2 1s mmvm. JOSEPH BAXTER Jr: Y

B WMAM AT T ORNE Y5 Patented Nov. 30, 1954 United States Patent Office SEALING MEANS FOR CYLINDER PAPERMAKING MACHINES Joseph Baxter, Jr.,.Franklin, Ohio, assignor to The Black- Clawson Company, Hamilton, Ohio, a corporation of Ohio This invention 'relates .to paper machinery, and more.

particularly to paperjmachines and stock thickeners of the cylinder type which include a vat having a-cylmder mold mounted for rotation therein. r

In the operation of apparatus of this type, both'for paper making and for stock thickening, a lower liquid level is maintained within the cylinder mold than in the portion of the vat outside the mold in order tocreate a partial vacuum within the mold drawing the white water through the perforate or foraminous mold face, and thus causing the fiber to be deposited on the outer surface of the mold while the white water is discharged through the open ends of the mold to the discharge outlets of the vat. Since the cylinder mold rotates continuously. in operation, it requires running clearance with respect to the adjacent end walls of the vat, and unless this clearance area is effectively sealed, not only will the effective vacuum and suctionithrough the mold face he reduced, but fiber will be drawn directly through this area and either be lost or 'elsemust be subsequently recovered from the white water. I to provide effective seals for this purpose, but in general they have resulted in relativelycomplex sealing devices and arrangements which have beencomparatively expensive as well as difficult to install and maintain".

It is accordingly the principal object of the present invention to provide asealing device for .the space between the ends of the cylinder mold and the end walls of a vat which is simple and economical to construct, install and replace, which offers low. frictional resistance to rotation of the cylinder mold in operation, which does not require special adjustment or alignment between the mold and the vat walls, and which provides a substantially complete seal around the entire circumference of the end of the mold.

It is also an object of the invention to provide a sealing device for the above purpose which may with equal ease be built into a new cylinder machine or thickener or be installed on an existing cylinder mold without requiring modification or reconstruction of the adjacent end walls of the vat.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claim.

In the drawing- Fig. l is a top view showing a stock thickener of the vat type embodying a sealing device for the ends of the cylinder mold constructed in accordance with the present invention;

Fig. 2 is an enlarged fragmentary section on the line 2-2 of Fig. 3 showing the sealing device and associated retainer on the end of the cylinder mold;

Fig. 3 is a view of the sealing device looking from right to left in Fig. 2 with the cylinder mold and fitting removed;

Fig. 4 is a section similar to Fig. 2 showing another form of the sealing device especially adapted for use on an existing cylinder mold; and

Fig. 5 is a somewhat diagrammatic view illustrating the use of the sealing device of the invention to provide a substantially complete 360 seal around the end of a cylinder mold.

Referring to the drawing, which illustrates preferred embodiments of the invention, the thickener in Fig. 1 includes a vat having end walls 11 and an overflow outlet lip 12 to the discharge trough 13 for the thickened stock, the discharge being controlled by a transfer roll Many attempts have been made.

troughs 16 at either end of the vat are provided with adjustable overflow gates 17, and their lower ends are fitted at 18 for attachment to suitable conduit pipes. The cylinder mol'd 20 is mounted for rotation in the vat by means of bearings 21 and is driven by the motor 22 through a pinion 23 and large gear 24, and Fig. 5 shows the usual couch roll 25. In operation, the thin stock enters the vat at 26 by way of a suitable inlet flow trough, not shown, and the whitewater drawn through the face of the mold passes out through the open mold ends to the outlet troughs 16. The overflow gates 17 are adjustable to vary the white water level within the interior of the mold in order to establish the proper difierence in head between the stock in the outer portion of the vat and the white water within the mold and thus to maintain the desired vacuum within the mold.

For maximum efficiency in operation, it is desirable to seal as completely as possible the clearance space necessarily present between the ends of the mold and the adjacent end walls 11 of the vat, and a sealing device provided for this purpose in accordance with the present invention is shown in detail in Figs. 2 and 3. One of the end spiders 30 of the mold 20 is shown fragmentarily in Fig. 2, together with one of the supporting rods 31 for the wire covering 32 which forms the foraminous mold face. As shown, the spider 30 is open at 33 between its spokes opening 35 in the vat wall 11 into the adjacent outlet trough 16. The outer end of the spider 310 includes an annular flange 40, and this flange is proportioned to extend into closely spaced relation with the vat wall 11 and is beveled at 42 to provide a frusto-conical surface relation towards-the adjacent vat wall 11 to seal the It is desirable against rotation with the mold,

space therebetween as shown in Fig. 2. to hold the sealing ring and this may be done by means of the retainer 45 and mounted on vat wall 11. The member 44 is formed of a flexible material having a low coefficient of friction such as a natural or synthetic rubber, and highly satisfactory results have been obtained in practice with this member 44 formed of a tube of the synthetic resin commercially available under the trade name of Koroseal, which has the advantages of high strength and toughness as well as low frictional qualities, especially when constantly lubricated with water as normally occurs in the practice of the invention.

The sealing ring 44 is provided with an inner core 50 shown as a relatively stiff helical spring having the coils thereof relatively close together to support the tube 44 against compression, and the spring core Sill may be secured within the tube coils thereof in the material of the tube, which is readily done by heating the spring core temporarily to soften the plastic material of the tube. In order to hold the ends of the tube 44 together and thus to form it into a substantially continuous ring, a more flexible spring portion 51 is provided at each end of the core 50, and these spring portions 51 are proportioned for connection under suflicient tension to retain the ends of the: tube 44 in abutting relation as shown in Fig. 3.

Assembly of the device and improved results in operation are obtained by connecting the spring portions 51 by means of the retainer 45, which is shown as a block bolted at 53 to the vat wall 11 and having a bore 54 therethrough which has a rod 55 slidably received therein. The lower end of the rod 55 carries a double ended book 56 adapted for connection with the outer ends of the spring portions 51, and semi-cylindrical notches 57 are provided in the ends of the tube 44 for receiving rod 55 so that when the two spring ends are secured to hook 56, the ends of the tube 44 will be drawn tightly together as shown.

Preferred results are obtained in accordance with the invention if the parts are so proportioned that when the sealing member 44 is mounted in position as shown,

it will be under sufiicient circumferential tension to seat 34 to provide direct communication through the 44 by partial embedding of the aeeaaso,

on the beveled surface 42 in such cammed relation therewith that it willbe constantly urged againstthe vat wall 11. Thus the beveled surface 42 and the tension provided in the sealing member will combine to urge the. sealing. member; into wedged relation with? both. the surface 42- and the surface of the; vat wall. to; form. an effectively tight seal. around the; entire circumference of the mold, and since: the suction; condition within the mold in operation will tend: only to draw the sealing member more tightly into this sealing: position, highly effective sealing. of the. junction between the. fitting andvat wall. 11 will; be: constantly maintained. At the same time, withthe part 441. formed of material properly chosen; for low friction; with respect tothe: surface' 42', asis; obtained; with. the: Koroseal: material; noted above, there is little frictional. resistance" to-rotation. of. the mold and correspondingly: low: wear on the sealing members.

In addition to. its. simplicity of construction. and: efl'lciency in operation, the sealing device. of the invention-v has outstandingpractical advantagesxfrom. the. standpoint of ease of installation; and replacement Since the sealing ring isarranged for" direct. engagement with. the adjacent. surface of. the vat wall; special: construction.- of the wall and careful fitting of thepartstin manufacture and assembly are not. required, and also'there is considerable allowable. tolerance. for variation: between. the overall length of the mold. and: the length of the: space between the end walls of. the vat in which the. mold is received. Thus. the initial installation of the sealing. device: and: the replacement of awornv sealing memberare equally quick and easy; requiring. only that the new: sealing member be threaded: around the end. of the moldand its, two spring ends, be.- connected to. the retaining. hook.

A specialadvantagelof"the. sealing: device of the invention lies. in thefactz that; the junction between the ends of the sealing member 4:4: may readily be located below the liquid. level. in the outer part of the: vat whereit is desired to seal substantially completely against the. passage: of. air. between the vat. walls and the: ends of the cylinder mold. As. shown in Fig; 5,. the retainer 45 mayreadily. be installed: below.- the: level 80 of stock outside the vat so that. they junction. of the ends of member 44 will. be. completely covered by the. stock, the level of; white water. within the mold' being indicated at 81*.

This: arrangement is especially useful where it: is desired 4. end construction for discharge of the white water. The spider is formed with an axiallyprojeeting annular flange which in a conventional construction of scaling device is carefully aligned with a similar flange on the vat wall 66 to support a sealing strap. In accordance with the present invention, however, a ring 70 having a beveled outer surface 72 isshrunk or otherwise secured on the flange 65*. for cooperation with. a. sealing ring 75 of the same construction as; shown in Figs. 2 and 3, thus providing the same practical advantages already described i'n-i connection. with the; form. of the invention. shown; Figs. 2.: and: 3 andi it. willv be apparent that; the length of the ring 70 may readily be altered as required to fit in properly close relation with the vat Wall.

While the forms ofapparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made: therein without. departing frorm the; scope: of; the

invention which is: defined: in; the appended claim.

What is claimed is}:

In combination with a cylinder mold. mounted. for rotation in. at vat. having; a flat vertical. end wall and provided. with: means. for. maintaining a lower liquid level within said, mold; than; in; the. portion:v of the vat outside said mold, sealingv means; for the junction between.- said flat wall and: the: adjacentv end of said mold comprising. means.- forming an outwardly converging frusto-conical end-surfaceon;said1endof said mold said might. exist at the junction. of the ends: of the sealing I member will; be effectively sealed: against in leakage of; air by; the: pressure. of the liquid stock' above this junction The invention is readily applicable to anexisting covering 62- and having spokes 63 providing an open mold: being; proportioned. to; fitlwithin. said: vat. with; the smallerv end of said: surface; in; closely: spaced. relation. with said; flat. vat wall; a sealing; member of flexible material. proportionedv to= encircle. said? frusto-conical surface, means; for. resiliently connecting. the endsof said sealing member: to form said; member: into a substantially continuous. ring; seated: on: said; frusto-conical: sun:- face in; rotatably. wedged.- relationwittr saidlsurface: and. said; flat; vatrwalhandi means on; said: wall for retaining.

, said: connected. ends of; said sealing member: on; said be continuously cammed; by saidifrustogconicalt surface into saidwedged: relation therewith mid. with; said vat; wall.

References Cited: imther-file of this patent. 7

UN T D A ENT-5' Number: Name Hate 88%,482. Gaara ..M ay= 26;. 1.908v 953,744.- Gaaraa Apr; 5:, 19510:

1,161,747 Stamets .N'ov 23,.1915" 1,166,882. Beaumonte Jim.- 4,. -16

2,-S3;6,634 Hubbard. Dec.. 26, 1.950

2,598,094 Augereau May" 27, 195 -21 FOREIGN PATENTS Number Glountry Date 15115697" Germany: FCbl- 22,. 119-033 

